/**
 * Copyright (c) 2005-2012 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.eqxiu.ieditor.commons.crypt;

import java.security.SecureRandom;
import java.util.HashMap;
import java.util.UUID;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * @author calvin
 * @version 2013-01-15
 */
public class Identities {

	private static SecureRandom random = new SecureRandom();

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间有-分割.
	 */
	public static String uuid() {
		return UUID.randomUUID().toString();
	}

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
	 */
	public static String uuid2() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}

	/**
	 * 使用SecureRandom随机生成Long. 
	 */
	public static long randomLong() {
		return Math.abs(random.nextLong());
	}

	/**
	 * 基于Base62编码的SecureRandom随机生成bytes.
	 */
	public static String randomBase62(int length) {
		byte[] randomBytes = new byte[length];
		random.nextBytes(randomBytes);
		return Encodes.encodeBase62(randomBytes);
	}
	
	public static void main(String[] args) {
//		System.out.println(Identities.randomLong());
//		System.out.println(Identities.randomBase62(6));
//		System.out.println(Identities.uuid2());
		
		HashMap<String,String> map = new HashMap<String,String>();
		long s = System.currentTimeMillis();
		for(int i=0;i<1000000;i++){
			String str = randomBase62(6);
			if(map.get(str) != null){
				System.out.println(str+"---------repeat-------");
			}
			map.put(str, "1");
		}
		System.out.println(System.currentTimeMillis()-s);
	}
}
